The Rooney Rule was introduced to the NFL in 2003. Illustration: Matt Johnstone

One of the most spirit-lifting moments during the NFL's latest visit to London – to these eyes, at least – came when two black head coaches, Mike Tomlin of the Pittsburgh Steelers and Leslie Frazier of the Minnesota Vikings, shook hands: the first time, surely, that two black managers have done so at Wembley. For Americans, however, the gesture was as unremarkable as the Lite beer. Since the introduction of the Rooney Rule in 2003, which compels NFL teams to interview at least one minority candidate for head coach and general manager jobs, these handshakes are frequent enough that few notice. That is how is should be.

The before-and-after makeover is striking. Before the Rooney Rule there were six black NFL head coaches in more than 80 years. In the decade since 12 have been hired. They are succeeding, too: at least one minority head coach or general manager has made the Super Bowl every year since 2006. Frazier, for one, believes it has changed his life. "The opportunities I've had to interview with other teams is the reason I am a head coach now," he said. "Prior to the Rooney Rule it was difficult to get before owners. The Rule opened things up."

Listening to Frazier, and reading Sol Campbell lament his lot in Saturday's Guardian, you wondered whether English football will ever follow the NFL's lead. The PFA has lobbied for the Rooney Rule, and has drawn up a 30-strong "Ready List" of black coaches keen on coaching and managerial positions but there is no great swell behind it. Most Britons seem instinctively more comfortable with no action than affirmative action; trusting instead in a vague sense that things will right themselves.

But will they? There are only four black and ethnic minority managers among the 92 English league clubs (the figure has bobbed between two and four for most of the past decade), even though around 25% of professional players and 18% on PFA coaching courses are black or from other ethnic minorities.

Ah, say the sceptics: look at the 2011 census. Only 5.6% of people in the UK are black or mixed white/black, so there is nothing to worry about. Then come other familiar refrains: if a manager is good enough they will get their chance, because no club would undermine their chances of success by not appointing the best candidate; that the Rooney Rule is reverse racism, because it gives minority managers favourable treatment; that, condescendingly, adopting it would be "tokenism".

These objections are – almost word for word – the same objections heard in the US before the Rooney Rule was enforced; objections that have since been shot down by the New York University Law Review. It found that: "Despite ongoing allegations that it promotes tokenism and is a form of reverse discrimination, the Rule has reached uncharted success."

Their key point was that while the NFL's "decision makers unwittingly held (and often still hold) archaic biases regarding the intellectual ability of minority candidates … the Rule has proven effective because it forces decision makers harbouring this unconscious bias to come face-to-face with a candidate they would never have considered otherwise."

Is English football any less unconsciously biased? A study in the Journal of Ethnic and Racial Studies, which interviewed 1,000 fans and former players, suggests not. It found "56% of respondents believe racism operates at the executive levels of football, ie the boardroom", with most suspecting "a form of unwitting or institutional racism".

You can understand why minority coaches get frustrated. If the road ahead is likely to be blocked, why start the journey? It is not as if manager's jobs are scarce in English football. In every season since 1998-99 at least a third have been sacked: often the figure is closer to half. Yet despite this great churn the same faces keep getting on and off (and on) the carousel.

What we don't know, however, is the percentage of minority coaches who apply for manager's jobs and get an interview – or a job – compared with other ethnic groups. The Rooney Rule came about in the NFL following a report showing white coaches with minimal experience were often hired over better qualified black coaches. The fear of litigation concentrated minds.

Some point out that of the 192 Uefa Pro Licence owners in England only 14 are held by minority coaches but that is not an essential requirement for a manager's job in the lower leagues. A Uefa A or B licence would suffice. Introducing the Rooney Rule in League One, League Two and the Conference, say, could be a game-changer. It would not force teams to appoint a minority candidate: merely to interview one when a vacancy arose. It is a nudge, not a shove. But look at the dramatic effect it had in the NFL.

Not that the Rooney Rule is perfect. When a team have a definite candidate in mind, the process can become an elaborate charade – although that happens in other businesses too. Some also fear that its impact in the NFL has stalled given that no minorities were among the eight head coaches appointed in 2013. No one, however, disputes that the NFL has more pathways for minority coaches to succeed than it did a decade ago. Can we say the same about English football?